Alternate forms of calling some the Big Cheese.

I have a character with an important father. Since the main character is the Junior, I'm getting tired of switching between calling the father -- His father / my father /etc or variations of Jason Senior.
In my quest for variety, I've found several ways the kid can refer to the man in a sarcastic manner but some of the terms would be out of place for a society a few thousand years in the future and not on Earth.

I've had to reframe from calling him Mayor McCheese, The Big Galoo, and The Grand Poo-Ba.

Choices I've found that work are:
The Grand Muckety-muck
The Grand Wizard
The Lion King
The Big Cheese
The Imperial Asshole Himself
Lord High Holyness
Dad

So ... I'm looking for more of these types of idioms. Anyone have suggestions?